| In this thesis we develop a nonlocal resonant theory for ab initio calculation of the cross sections for low-energy electron diatomic molecule collisions. The processes studied are dissociative attachment (DA), vibrational excitation (VE) and collision-induced resonance dissociation. Results are presented for two simple but representative molecules. Although the e-H2 scattering has been studied in many other works previously, the present study extends the theoretical description to processes involving highly excited rovibrational states of H2. These processes were experimentally found to be the dominant mechanism for the creation of negative ions in many hydrogen plasmas. The HF molecule represents the family of molecules for which the long range dipole interactions with the electrons are important.; The present work is helpful for understanding the low energy e-H 2 scattering process, including especially the dissociative attachment to the H2 molecule. The cross sections obtained here can be directly applied to the modelling of low-density hydrogen discharges and recently discovered molecular activated recombination in fusion divertor plasmas. The cross sections for DA and VE of HF agree well with available experimental results. The complicated structures in the experimental DA and VE cross sections for polar molecules, i.e. the step-wise structure in the DA cross sections at the opening of each VE threshold, the threshold peak, vibrational Feshbach resonance and boomerang oscillations in the VE cross sections are all explained quantitatively for the HF molecule. |
